Until recently, this species was included in M. annularis (Weil and Knowlton 1994) along with M. franksi. Consequently, most studies prior to 1994 do not distinguish between the three species, and information on population is difficult to disaggregate for the three taxa.

Justification:
This species is listed as Endangered as the species is believed to have undergone a decline exceeding 50% over the past 30 years due in particular to the effects of disease and bleaching, as well as other factors. Current rates of mortality are exceeding growth and recruitment, and current threats are increasing and spreading into new areas. Due to their extreme longevity, low rates of recruitment and long generation times, scope for recovery of populations is limited. If current trends continue, this species may warrant listing in a higher category of threat.

In the last 20 years, there has been a severe decline in the overall cover and abundance of M. faveolata in several parts of the Caribbean. For example, 90% of the species was lost in the coastal waters off Jamaica from 1980 through 1994 (Hughes, 1994). Off the coast of eastern Puerto Rico, declines in cover were recorded at between 40 and 60% (Hernandez-Delgado 2005), at around 40% off south-eastern PR (E. Weil pers. comm.), 40-80% off Desecheo Island and Mona Island (Bruckner and Bruckner 2006, A. Bruckner pers. comm.), and 72% in St John, US Virgin Islands, between 1988 and 1999 (Edmunds and Elahi 2007). Dustan and Halas (1987) observed a 31% decline in cover of M. faveolata on Carysfort Reef (Key Largo) between 1975 and 1982, with a 21% decline in colony size.

The age of first maturity of most reef building corals is typically three to eight years (Wallace 1999) and therefore we assume that average age of mature individuals is greater than eight years. Furthermore, based on average sizes and growth rates, we assume that average generation length is 10 years, unless otherwise stated. Total longevity is not known, but likely to be more than ten years. Therefore any population decline rates for the Red List assessment are measured over at least 30 years. Follow the link below for further details on generation length estimates.

The major threats to the species are infectious diseases (e.g., plague, yellow band and black band disease) and bleaching. Other threats include predation by Sparisoma viride (Stoplight Parrotfish), hurricane damage, and loss of habitat at the recruitment stage due to algal overgrowth and sedimentation, as well as localized impacts due to bioerosion by sponges and other organisms, and other diseases.

In general, the major threat to corals is global climate change, in particular, temperature extremes leading to bleaching and increased susceptibility to disease, increased severity of ENSO events and storms, and ocean acidification.

Coral disease has emerged as a serious threat to coral reefs worldwide and a major cause of reef deterioration (Weil et al. 2006). The numbers of diseases and coral species affected, as well as the distribution of diseases have all increased dramatically within the last decade (Porter et al. 2001, Green and Bruckner 2000, Sutherland et al. 2004, Weil 2004). Coral disease epizootics have resulted in significant losses of coral cover and were implicated in the dramatic decline of acroporids in the Florida Keys (Aronson and Precht 2001, Porter et al. 2001, Patterson et al. 2002). Escalating anthropogenic stressors combined with the threats associated with global climate change of increases in coral disease, frequency and duration of coral bleaching and ocean acidification place coral reefs at high risk of collapse.

In the US, it is present in many MPAs, including Florida Keys National Marine Sanctuary, Biscayne N.P., Dry Tortugas National Park, Buck Island Reef National Monument and Flower Garden Banks National Marine Sanctuary. Also present Hol Chan Marine Reserve (Belize), Exuma Cays Land and Sea Park (Bahamas). In US waters, it is illegal to harvest corals for commercial purposes. (Aronson, R., Precht, W., Moore, J., Weil, E., and Bruckner, A. pers. comm.)

All corals are listed on CITES Appendix II.

Recommended measures for conserving this species include research in taxonomy, population, abundance and trends, ecology and habitat status, threats and resilience to threats, restoration action; identification, establishment and management of new protected areas; expansion of protected areas; recovery management; and disease, pathogen and parasite management. Artificial propagation and techniques such as cryo-preservation of gametes may become important for conserving coral biodiversity.